This is a small app that shows yo how to use simple UICollectionViewFlowLayout sublcasses and transition between them. You can get a lot of really nice layouts without any further modification than init.

Demonstrates:

• Custom UICollectionViewFlowLayout subclasses.
• How to implement UICollectionViewCell subclasses.
• How to change layouts (with animation).
• How to set up a collection view without a .xib or Storyboard.

More notes here.